A great deal of research is currently underway to develop treatments and cures for viral infections in humans and in animals. Notably the incidence of AIDS and ARC in humans is increasing at an alarming rate. The five year survival rate for those with AIDS is dispiriting and AIDS patients, whose immune systems have been seriously impaired by the infection, suffer from numerous opportunistic infections including Kaposi's sarcoma and Pneumocystis carninii pneumonia. No cure is known and current treatments are largely without adequate proof of efficacy and have numerous untoward side effects. Fear of the disease has resulted in social ostracism of and discrimination against those having or suspected of having the disease.
A significant problem in preventing the spread of AIDS is that the disease can be transferred from an infected individual by way of a blood transfusion or through the use of blood products, such as the coagulation factor VIII used by many hemophiliacs and such as blood serum and blood plasma, using blood donated from an individual infected with an AIDS-causing virus. The problem is confounded because intravenous drug users, who as a class have a high incidence of AIDS, are also quite likely to be blood donors. While an effective test has been developed which detects HIV-1 virus in blood donated for transfusions, some transmission of disease still occurs through blood tranfusions. For example, some individuals are highly infectious for up to six months before the test will indicate presence of AIDS-causing virus in the blood of such individuals. Moreover, a second AIDS-causing virus, HIV-2, is not detected by the present blood test. While the risk of contracting AIDS from transfusion is quite low because testing has become routine, it would be highly desirable to further reduce the risk of transmission of AIDS-causing virus resulting from blood transfusions.
The quaternary ammonium salts have long been known to possess topical antiseptic and disinfectant properties. For example, cetylpyridium chloride has long been known to posssess antimicrobial activity and has been used in mouthwashes and as a topical antiseptic and as a disinfectant for many years. The benzalkonium chlorides are widely used in disinfectant products. The quaternary ammonium salts are known to be quite effective against gram positive bacteria and to a lesser extent are effective against the gram negative bacteria. These salts, in particular, the benzalkonium chlorides, are not known to be significantly anti-viral. Only recently has the anti-AIDS virus activity of the benzalkonium chlorides been recognized when employed in a contraceptive cream.
While crystal blue, an antiseptic dye, has been used for many years in tropical countries to prevent the transmission by blood transfusion of various parasitic diseases such as African trypanosomiasis and Chagas' disease, the use of this and other quaternary ammonium salts to prevent disease transmission by blood transfusion has not been actively pursued despite the overwhelming need for such prophylactic therapy. Surprisingly, it has now been found that the quaternary ammonium salts, in particular cetylpyridinium chloride, can inactivate AIDS-causing virus in donated whole blood intended for use in blood transfusions and in the preparation of other blood products. Such finding is all the more surprising because the benzalkonium chlorides and to some extent cetylpyridium chloride as well as all the other quaternary ammonium salts are known to be deactivated by contact with living tissue and thus the quaternary ammonium salts have been used only topically. Applicant's unexpected discovery should prove most useful in the prevention of the transmission of this insidious disease.